1. Field of the Invention
The present invention relates generally to a reciprocating compressor, and more particularly, to a reciprocating compressor having a discharge pulsation reducing structure for reducing noise made during the discharge of refrigerant step.
2. Description of the Related Art
A general reciprocating compressor is used in refrigerating machines, such as refrigerators and water cooling machines, for compressing low pressure gas refrigerant into high pressure refrigerant.
As shown in FIG. 1, a conventional reciprocating compressor comprises a case 10 comprised of an upper shell 11 and a lower shell 12, a compression unit 30 disposed inside the lower part of the compressor and comprised of apparatuses for compressing refrigerant, and an electrically-driven unit 20 for driving the compression unit 30.
The compression unit 30 comprises a cylinder head 60 having a refrigerant suction chamber 61 and a refrigerant discharge chamber 62, a cylinder block 70 having a compression chamber 71 in which refrigerant is compressed, a valve assembly 80 controlling the flow of refrigerant between the cylinder head 60 and the cylinder block 70, a piston 50 disposed inside the compression chamber 71, and a connecting rod 40 moving the piston 50 to reciprocate linearly.
The electrically-driven unit 20 for driving the compression unit 30 comprises a stator 21 fixed to the case 10, a rotor 22 rotating by means of electromagnetic reciprocating operation relative to the stator 21, and a crank shaft 23 press-fit in the rotor 22 and having an eccentric portion 23a. The eccentric portion 23a is connected to the connecting rod 40.
As shown in FIG. 2, a protruding discharge muffler 72 is provided at the bottom of the cylinder block 70. The discharge muffler 72 is connected with a refrigerant discharge pipe 74, which is connected to a condenser (not shown) and the discharge muffler 72 is sealed by a muffler cover 73. In addition, the discharge muffler 72 is connected to a refrigerant path 75 formed through the cylinder block 70. The refrigerant in the refrigerant discharge chamber 62 flows into the discharge muffler 72 through the refrigerant path 75.
In the above-described conventional compressor, as shown in FIGS. 1 and 2, the refrigerant flows into the compression chamber 71 sequentially through a refrigerant suction pipe 91, a muffler 90, and into the refrigerant suction chamber 61, and is discharged into the refrigerant discharge chamber 62 after being compressed by linear reciprocation of the piston 50. The refrigerant discharged into the refrigerant discharge chamber 62 flows into the discharge muffler 72 through the refrigerant path 75 and then into the condenser through the refrigerant discharge pipe 74.
However, in such a conventional reciprocating compressor, discharge pulsation occurs because the piston 50 in the compression chamber 71 sucks in, compresses, and discharges the refrigerant while linearly reciprocating. Such discharge pulsation of the refrigerant causes noise and vibration in the compressor. Particularly, since the vibration of the compressor occurs at the acoustic low frequency band corresponding to the natural or resonant frequency of other parts of the refrigerator, this creates resonance with other parts of the refrigerator. This resonance causes noise and vibration to increase in the overall refrigerator during operation.
The discharge pulsation of the refrigerant may be reduced by increasing the flow resistance of the discharge refrigerant. That is, the discharge pulsation of the refrigerant may be reduced by reducing the sectional area of the refrigerant path 75 between the refrigerant discharge chamber 62 and the discharge muffler 72, or lengthening the refrigerant path 75, either of which causes an increase in flow resistance. However, when the sectional area of the refrigerant path 75 is too small, the refrigerant cannot flow smoothly between the refrigerant discharge chamber 62 and the discharge muffler 72, and therefore the compression efficiency of the compressor drops. In addition, the refrigerant cannot be sufficiently lengthened as it is formed through the cylinder block 70.
In order to solve the above-mentioned problem, the present invention has been developed to provide a reciprocating compressor capable of efficiently reducing the discharge pulsation by improving the refrigerant discharge structure.
In order to achieve the object of the present invention, the reciprocating compressor comprises a main frame disposed inside a case to support an electrically-driven unit, a cylinder block connected with the main frame and having a compression chamber, a cylinder head having a refrigerant discharge chamber and connected with the cylinder block to seal the compression chamber, a first chamber formed at one side of the cylinder block to be connected with the refrigerant discharge chamber, a second chamber connected with a refrigerant discharge pipe and formed at another side of the cylinder block, and a gasket disposed between the main frame and the cylinder block, the gasket having a groove for providing a connecting path connecting the first chamber and the second chamber and thus fluid communication between the chambers.
Accordingly, discharge pulsation is reduced as the compressed refrigerant flows through the first chamber, the connecting path, and the second chamber before being discharged through the refrigerant discharge pipe.
In the above-described structure, it is preferable that a first oil chamber corresponding to the first chamber is disposed at one side of the main frame adjacent the first chamber, and a second oil chamber corresponding to the second chamber is disposed at another side of the main frame.
In addition, it is preferable that the first and the second chambers have a height of between about 14 mm and 30 mm and a volume of between about 15 and 25 cc.
The connecting path has a cross sectional area of between about 2.5 and 10 mm2.
It is preferable that the first and second oil chambers have a volume of between about 8 and 10 cc.
It is preferable that an insertion hole is formed at one side of the second chamber, and the refrigerant discharge pipe is connected with the refrigerant discharge tube inserted in the insertion hole.